1. Technical Field
Various embodiments of the present invention relate to an electro-optical device including a mirror, a method of manufacturing the electro-optical device, and an electronic apparatus.
2. Related Art
For example, a projection display device, which modulates light emitted from a light source using a plurality of mirrors (micro mirrors) of an electro-optical device called a digital mirror device (DMD), enlarges the modulated light to project using a projection optical system, thereby displaying an image onto a screen, is known as an electronic apparatus. In the electro-optical device which is used for the electronic apparatus, the mirror is supported by a torsion hinge (twist hinge) through a mirror support post, and is electrically coupled to the torsion hinge. In addition, the torsion hinge is supported by a bias electrode on a substrate side which is formed in the substrate through a hinge support post, and is electrically coupled to the bias electrode on a substrate side. Thus, while a bias voltage is applied to the mirror from the bias electrode on a substrate side, if a drive voltage is applied to an address electrode, it is possible to drive the mirror using an electrostatic force which is generated between the mirror and the address electrode. In manufacturing steps of an electro-optical device having the configuration, a torsion hinge, a mirror, or the like is formed by using a sacrificial layer which is configured by a resin material.
Here, if the mirror support post faces the concave portion at a side opposite to the substrate, a large dent is formed on a surface of the mirror, and thereby reflectance of the surface (reflective surface) of the mirror decreases. Thus, a technology, in which an inorganic material is accumulated to a surface of the mirror support post, the sacrificial layer or the like, the surface is ground, and thereafter the reflective film that forms the mirror is formed, is proposed (refer to JP-T-2007-510174). In addition, a configuration, in which a metal layer is formed on a surface of a columnar sacrificial layer (resin layer) remaining on a torsion hinge when a mirror support post is formed, is proposed (refer to JP-A-8-227042).
However, in the same manner as a configuration described in JP-T-2007-510174, in order to fill a concave portion by accumulating an inorganic material, it is necessary to quite thickly accumulate the inorganic material, and in a case of the inorganic material, grinding speed is delayed. For this reason, there is a problem in which a long processing time is required to grind the inorganic material for removal from a surface of a sacrificial layer or the like.
In addition, in the same manner as a configuration described in JP-A-8-227042, if a mirror support post is formed by laminating a metal layer on a columnar resin layer, when the temperature of the electro-optical device is increased due to the light which is incident, or heat which is generated in the substrate at the time of operating a drive circuit, or the like, there is a possibility that gas is generated from the sacrificial layer. If the gas is attached to a surface (reflective surface) of the mirror, reflectance of the mirror is decreased, and thus the gas is not desired. In addition, in order to form a torsion hinge (twist hinge) and a mirror support post, steps of forming a metal layer with two layers and forming an intermediate layer with an insulating property between the metal layers of two layers for patterning are required, and thus a manufacturing step of the electro-optical device is complicated.